Fractures are extensively distributed in underground rocks, have all-important influence on propagation of seismic waves and also play a critical role in storing and migrating subsurface fluids. Therefore, feature description of formation fractures is an important research content of fractured oil and gas reservoirs. Under the action of tectonic movement, rocks will generate high-angle fractures, also called vertical fractures, which are major research objects in conventional oil-gas exploration. Besides, in shale and coal beds, horizontally-distributed natural fractures, also called horizontal fractures, are developed under the influence caused by factors such as oriented arrangement of minerals and action of geostress. Wherein, the horizontal fractures provide reservoir spaces for shale gas and coal-bed gas and play an all-important role in gas content of reservoir beds, so that the prediction of the horizontal fractures has an important significance in exploration and development of the shale gas, the coal-bed gas, etc.
The existing fracture prediction methods, for example a shear-wave splitting (SWS) based formation fracture prediction method can only be used for effectively predicting the vertical fractures and cannot be used for identifying the horizontal fractures during the prediction of the fractures.
In view of how to predict the horizontal fractures, an effective solution is not proposed yet at present.